Auxiliary flotation for reducing the draft of ships

ABSTRACT

Auxiliary flotation means for reducing the draft of a ship so that it may operate in shallower waters. A plurality of expansible pneumatically inflatable bellows shaped flotation bags supported from a load-bearing structure which is pivotally and slidably supported from tracks on the side of the ship. A control arm pivotally connected to the side of the ship and slidably connected to the load-bearing structure for rotating the bags outwardly from the ship and into a supporting position, and for rotating the bags inwardly against the side of the ship and into a raised retracted position. Stop means are provided at the lower end of the track for limiting the downward sliding movement of the load-bearing structure to place the structure in the horizontal position. Hydraulic piston and cylinder means are connected between the control arm and the ship for rotating the control arm and for holding the load-bearing structure to a horizontal position when the bags are inflated. And a buoyancy chamber may be connected to the outer end of the load-bearing structure to assist in rotating the load-bearing structure to a horizontally extended position.

llnite States Patent Black et a1. 5] ct. 29, 1974 1 AUXHLIARY FLOTATION FOR REDUCING THE DRAFT OF SHIPS 57 ABSTRACT [75] Inventors: Harry G. Black, PO. Box 3237,

Galveston, Tex. 77550; Lowell B. Christenson, Houston, Tex.

[52] 11.8. C1. 114/123 [51] Int. Cl B631) 43/14 [58] Field of Search 114/123, 49, 52-54 [56] References Cited UNITED STATES PATENTS 1,355,937 10/1920 Brosnan ..114/123 1,708,784 4/1929 Carloni 3,171,377 3/1965 Livas 3,198,157 8/1965 Livas 114/123 Primary Examiner-Trygve M. Blix Assistant ExaminerStuart M. Goldstein Attorney, Agent, or F irm-rjefferson D. Giller; James F. weileg william A. Stout Auxiliary flotation means for reducing the draft of a ship so that it may operate in shallower waters. A plurality of expansible pneumatically inflatable bellows shaped flotation bags supported from a load-bearing structure which is pivotally and slidably supported from tracks on the side of the ship. A control arm pivotally connected to the side of the ship and slidably connected to the load-bearing structure for rotating the bags outwardly from the ship and into a supporting position, and for rotating the bags inwardly against the side of the ship and into a raised retracted position. Stop means are provided at the lower end of the track for limiting the downward sliding movement of the load-bearing structure to place the structure in the horizontal position. Hydraulic piston and cylinder means are connected between the control arm and the ship for rotating the control arm and for holding the load-bearing structure to a horizontal position when the bags are inflated. And a buoyancy chamber may be connected to the outer end of the load-bearing structure to assist in rotating the load-bearing structure to a horizontally extended position.

9 Claims, 6 Drawing Figures PATENTED BT 29 L974 $844,241 vSHEEI 20$ 2 AUXILIARY FLOTATION FOR REDUCING THE DRAFT OF SHIPS BACKGROUND OF THE INVENTION The marine shipping industry is facing a crisis brought on by the tremendous increase of operating a ship which in turn can only be offset by increased freight charges. To combat rising costs, the size of ships have been increased to increase the amount of freight a ship can transport. While the increase in ship size re duces the cost per ton for ship operations, the size of the ship increases the draft of the vessel correspondingly. The increase in the draft of the vessel limits the number of ports that the ship can service and, therefore, limits the locations in which the larger ship can be utilized. The present invention is directed to providing means for reducing the draft of a ship, when loaded,

to the extent that it can enter existing seaports of shallower water thereby increasing the scope of the vessel activity which in turn will tend to reduce the cost of operation.

The use of inflatable flotation devices have been suggested in U.S. Pat. Nos. 3,171,377 and 3,198,157. The present invention is directed to an improved auxiliary flotation system for reducing the draft of ships.

SUMMARY The present invention is directed to providing a plurality of expansible pneumatically inflatable floating bags which are supported from a load-bearing structure which is pivotally and slidably supported from vertical track means on the side of the ship. A control arm is pivotally connected to the side of the ship and slidably connected to the load-bearing structure for rotating the bags outwardly into a ship supporting position and for rotating the bags inwardly into a raised retracted position against the side of the ship. Power means are connected between the control arm and the ship for rotating the control arm.

A still further object of the present invention is the provision of a buoyancy chamber connected to the outer end of the load-bearing structure to aid in rotating the structure to a horizontal position for rotating the flotation bags to an extended load-supporting position.

A still further object of the present invention is wherein the load-bearing structure is an L-shaped member connected to the bags on a side away from the ship, the smaller leg of the structure being pivotally connected at its free end to the track means. The control arm may also be L-shaped with the smaller leg being pivotally connected at its free end to the side of the ship with the free end of the longer leg being slidably and pivotally connected to the longer leg of the load-bearing structure.

Yet a further object is the provision of the inflatable bags in the form of an expansible and contractible bellows for providing a bag which will compactly retract and which when inflated will provide a retained shape for directing a buoyant force upwardly through the load-bearing structure.

Still other and further objects, features and advantages will be apparent from the following description of a presently preferred embodiment of the invention, given for the purpose of disclosure and taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, partly schematic, illustrating the position of attachment of the flotation systems of the present invention on one side of a ship.

FIG. 2 is an enlarged fragmentary elevational view, in cross section, illustrating the present invention in its retracted and non-load supporting position,

FIG. 3 is a fragmentary elevational view, in cross section, of the device of FIG. 2 shown in position ready to be inflated for supporting the ship,

FIGS. 4, 5 and 6 are elevational views, in cross section, showing the sequence of operation of the present invention with FIG. 4 showing the flotation bags being in the retracted position,

FIG. 5 showing the apparatus being rotated and positioned in an extended position, and

FIG. 6 showing the bags being inflated for decreasing the draft of the ship.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and particularly to FIG. 1, a conventional ship 10 is shown having a plurality of auxiliary flotation systems 12 folded against the side of the ship 10 in a retracted position while the ship 10 is sailing in deep waters. While the flotation systems 12 are shown on one side of the hull of the ship 10, similar auxiliary flotation systems are connected to the other side of the ship 10.

The auxiliary flotation systems 12 include, as best seen in FIGS. 2 and 3, a pneumatically inflatable flotation bag which, when inflated with compressed air supplied by the ship 10, would tend to lift the hull of the ship 10 higher in the water thereby reducing its draft. When inflated, for example only, the auxiliary flotation systems 12 would raise a ship drawing feet of water to a point so that the ship 10 would draw only 30 feet of water and would, therefore, be able to navigate into shallower channels and ports.

Referring now to FIGS. 2 and 3, the pneumatically inflatable flotation bags 14 may be of any suitable material such as reinforced nylon and are preferably in the form of a plurality of interconnected diaphragms 16 forming a bellows-like structure, which may be either circular or square in cross section.

In addition to the flotation bags 14, the flotation section 12 generally includes a load-bearing structure 18 and a control arm 20. The load-bearing structure 18 may include a plate 19 (FIG. 1) connected to and supporting the bags 14 such as by bonding the top of the bags 14 to the bottom of the plate 19. Track means 21 are provided vertically extending on the side of the ship 10. The smaller leg 22 of the L-shaped load-bearing structure 18 is pivotally connected at its free end by pivot 24 to a carriage member 26 slidably engaging the track 21. A stop member 28 is provided at the lower end of the track 21 limiting the downward movement of the carriage 26 whereby the load-bearing structure 18 may move from a retracted upward position, as best seen in FIG. 2, to an extended lowered position, as best seen in FIG. 3, extending horizontally from the side of the ship 10.

The control arm 20 is preferably L-shaped in cross section and may consist of one or more sets of control arms, the smaller leg of the L-shaped arm 30 being pivotally connected by pivot 32 to the side of the ship 10.

The free end of the longer leg 34 is pivotally and slidably connected to the load-bearing structure 18 through pivot 36, carriage 38 and a track 41 on the load-bearing structure 18. A stop 45 is provided in the track 41 limiting the extent of travel of the carriage 38 for rotating the structure 18 between a vertical position shown in FIG. 2 to a horizontal position, as shown in FIG. 3.

Suitable power means are provided for rotating the control arm 20 and in turn rotating the load structure 18 and bag 14 outwardly from the side of the ship 10 and into a lowered ship supporting position as shown in FIG. 3 and for rotating the load-bearing structure 18 and flotation bags 14 inwardly and against the side of the ship 10 into a raised retracted position as best seen in FIG. 2. Such means may include a double acting piston and cylinder assembly 40 pivotally connected between the side of the ship 10 and the control arm 20.

In order to assist the movement of the load'bearing structure 18 from the vertical position of FIG. 2 to the horizontal position of FIG. 3, a buoyant chamber 42 may be provided at the outer end of the member 18 which is connected to an air hose 43 for supplying air from the ship 10 to the chamber 42. Thus, when the control arm rotates the structure 18 outwardly from the ship 10, air may be supplied to the chamber 42 assisting in vertically moving the outer end of the structure 18 upwardly to place the load-bearing structure 18 in the horizontal position as shown in FIG. 3.

After the inflatable flotation bag 14 is rotated away from the side of the ship into a load-bearing position, as best seen in FIG. 3, air is supplied from the ship through a line, such as 46, to inflate the bag 14 to provide the necessary buoyancy for reducing the draft required for the ship 10. The upward buoyant force created by the inflated bag 14 is exerted through structure 18, arm 20 and piston and cylinder assembly 40 for application to the side of ship 10.

Referring now to FIGS. 4, 5 and 6, the steps of operation and retraction of the present invention is best seen. Normally, the ship 10, while traveling in deep waters, having a waterline 60, will have actuated the piston and cylinder assembly 40 to retract the control arms 20 moving the load-bearing structures 18 and inflatable bags 14 into a retracted position as best seen in FIG. 4. It is noted in FIG. 4 that the retracted position holds the structure 18 and deflated bags 14 in a raised position along the side of the vessel thereby protecting the auxiliary flotation assemblies 12. If additional streamlining of the assemblies 12 is desired, the assemblies can readily be positioned in recesses in the side of the vessel 10 although, as shown, they may be quickly and easily superimposed on the sides of existing vessels It). When it is desired to decrease the draft of the vessel 10, the hydraulic piston and cylinder assemblies 40 are actuated rotating the control arms outwardly allowing the support structures 18 and bags 14 to move downwardly on the track 21 and assume a generally horizontal position. The buoyancy of the chamber 42 provides additional power to rotate the structures 18 into the horizontal position ready for inflation of the flotation bags 14. In addition, the rotation and downward movement of the flotation bags 14 insures that the bags 14 will move deeper into the water so that when inflated will be able to raise the vessel 10 the desired amount.

As best shown in FIG. 6, when the bags 14 are inflated, they provide a buoyant force through the loadsupporting structure 18 and the control arm 20 to raise the vessel relative to the water 60 thereby reducing the draft.

The procedure for retracting the auxiliary flotation system 12 is the reverse of that for initiating operation. That is, first, the air is released from the flotation bags 14, and the cylinder and piston assembly 40 is actuated to control arm 20 downwardly. The chamber 42 may be ballasted with water, if desired, although this is not necessary as the interior end of the supporting structure 18 will be moved upwardly by the inherent buoyant nature of the bag 14 as the control arm 20 is rotated toward the side of the vessel 10.

It is to be noted that the bellows-shaped bags 14 are particularly advantageous in that when deflated and rotated to a retracted position, the bags 14 will assume a compact shape against the side of the hull of the ship 10. And when the bellows-shaped bags 14 are inflated, they will retain their expanded shape and direct the buoyant force upwardly against the load-bearing structure 18 without requiring any bag-retaining structure about the sides of the bags 14.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While a presently preferred embodiment of the invention is given for the purpose of disclosure, numerous changes in the detail of construction and arrangement of parts may be made which will readily suggest them selves to those skilled in the art and which are encompassed within the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. Auxiliary flotation for reducing the draft of ships comprising,

a plurality of expansible pneumatically inflatable flotation bags,

vertical track means directly secured and extending coplanar to the side of the ship and extending to an underwater position,

a load-bearing structure pivotally and slidably supporting each bag from said track means,

a control arm pivotally connected to the side of the ship and slidably connected to the load-bearing structure for extending the flotation bags outwardly into a lowered underwater position and retracting the bags into a raised retracted position against the side of the ship,

power means connected between the control arm and the ship for rotating the control arm.

2. The apparatus of claim 1 including,

a buoyancy chamber connected to the end of the load-bearing structure remote from the track means.

3. Auxiliary flotation for reducing the draft of ships comprising,

a plurality of expansible pneumatically bellowsshaped inflatable flotation bags,

vertical track means on the side of the ship,

a load-bearing structure connected to the bags on a side away from the ship, said load-bearing structure pivotally and slidably connected adjacent its upper end to said track means,

a control arm pivotally connected adjacent its upper end to the side of the ship and slidably connected to the load-bearing structure for rotating the structure and the bags outwardly into a lowered ship supporting position and for rotating the structure inwardly into a raised retracted position against the side of the ship, and

hydraulic piston and cylinder means connected between the control arm and the ship for rotating the control arm.

4. The apparatus of claim 3 including,

a buoyancy chamber connected to the end of the load-bearing structure remote from the track means.

5. The apparatus of claim 3 including a stop at the lower end of the track means limiting the downward sliding movement of the load-bearing structure on the track means.

6. The apparatus of claim 3 wherein the flotation bags are expansible and collapsible diaphragms.

7. Auxiliary flotation for reducing the draft of ships comprising,

a plurality of expansible pneumatically inflatable flotation bags,

vertical track means on the side of the ship,

an L-shaped load-bearin g structure connected to the bags on a side away from the ship, the smaller leg of the L-shaped structure being pivotally connected at its free end to said track means,

an L-shaped control arm, the smaller leg of the L- shaped arm being pivotally connected at its free end to the side of the ship, the free end of the longer leg of the L-shaped arm slidably and pivotally connected to the longer leg of the L-shaped load-bearing structure for rotating the structure and the bags outwardly from the ship and into a lowered ship supporting position and for rotating the structure inwardly against the side of the hip into a raised retracted position,

hydraulic piston and cylinder means connected betweeen the control arm for rotating the control arm,

stop means at the lower end of the track means limiting the downward sliding movement of the loadbearing structure on the track means for horizontally positioning the load-bearing structure.

8. The apparatus of claim 7 including,

a buoyancy chamber connected to the free end of the longer leg of the L-shaped load-bearing structure.

9. The apparatus of claim 7 wherein the bags are bellows-shaped. 

1. Auxiliary flotation for reducing the draft of ships comprising, a plurality of expansible pneumatically inflatable flotation bags, vertical track means directly secured and extending coplanar to the side of the ship and extending to an underwater position, a load-bearing structure pivotally and slidably supporting each bag from said track means, a control arm pivotally connected to the side of the ship and slidably connected to the load-bearing structure for extending the flotation bags outwardly into a lowered underwater position and retracting the bags into a raised retracted position against the side of the ship, power means connected between the control arm and the ship for rotating the control arm.
 2. The apparatus of claim 1 including, a buoyancy chamber connected to the end of the load-bearing structure remote from the track means.
 3. Auxiliary flotation for reducing the draft of ships comprising, a plurality of expansible pneumatically bellows-shaped inflatable flotation bags, vertical track means on the side of the ship, a load-bearing structure connected to the bags on a side away from the ship, said load-bearing structure pivotally and slidably connected adjacent its upper end to said track means, a control arm pivotally connected adjacent its upper end to the side of the ship and slidably connected to the load-bearing structure for rotating the structure and the bags outwardly into a lowered ship supporting position and for rotating the structure inwardly into a raised retracted position against the side of the ship, and hydraulic piston and cylinder means connected between the control arm and the ship for rotating the control arm.
 4. The apparatus of claim 3 including, a buoyancy chamber connected to the end of the load-bearing structure remote from the track means.
 5. The apparatus of claim 3 including a stop at the lower end of the track means limiting the downward sliding movement of the load-bearing structure on the track means.
 6. The apparatus of claim 3 wherein the flotation bags are expansible and collapsible diaphragms.
 7. Auxiliary flotation for reducing the draft of ships comprising, a plurality of expansible pneumatically inflatable flotation bags, vertical track means on the side of the ship, an L-shaped load-bearing structure connected to the bags on a side away from the ship, the smaller leg of the L-shaped structure being pivotally connected at its free end to said track means, an L-shaped control arm, the smaller leg of the L-shaped arm being pivotally connected at its free end to the side of the ship, the free end of the longer leg of the L-shaped arm slidably and pivotally connected to the longer leg of the L-shaped load-bearing structure for rotating the structure and the bags outwardly from the ship and into a lowered ship supporting position and for rotating the structure inwardly against the side of the hip into a raised retracted position, hydraulic piston and cylinder means connected betweeen the control arm for rotating the control arm, stop means at the lower end of the track means limiting the downward sliding movement of the load-bearing structure on the track means for horizontally positioning the load-bearing structure.
 8. The apparatus of claim 7 including, a buoyancy chamber connected to the free end of the longer leg of the L-shaped load-bearing structure.
 9. The apparatus of claim 7 wherein the bags are bellows-shaped. 